共查询到20条相似文献,搜索用时 0 毫秒
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Joon-Ho Lee Jiefu Chen Qing Huo Liu 《Antennas and Propagation, IEEE Transactions on》2009,57(9):2666-2674
A discontinuous spectral element time-domain method is proposed to analyze transient electromagnetic properties of general 3-D structures. This method is advantageous in that its mass matrices are block-diagonal due to the Gauss-Lobatto-Legendre polynomials, and it allows different orders of basis functions for each subdomain. The Riemann solver is employed in the boundary integral terms to communicate fields between adjacent subdomains. Perfectly matched layers are utilized to truncate the computational domain. Galerkin method is used for spatial discretization, and a fourth-order Runge-Kutta scheme is employed for the time integration. The validity of the proposed approach is demonstrated through several numerical examples of initial value problems and scattering problems. 相似文献
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A spectral-element time-domain (SETD) method is proposed to solve 3-D transient electromagnetic problems based on Gauss-Lobatto-Legendre polynomials. It has the advantages of spectral accuracy and block-diagonal mass matrix. With the inexpensive inversion of the block-diagonal mass matrix, the proposed method requires only a trivial sparse matrix-vector product at each time step, thus significantly reducing CPU time and memory requirement. Galerkin's method is used for spatial discretization, and a fourth-order Runge-Kutta scheme is employed for the time integration. The perfectly matched layer (PML) is employed to truncate the boundary in unbounded problems. The pseudospectral time-domain method is used to simplify the treatment of the PML inside the proposed SETD method. Numerical examples are shown to verify the efficiency and the spectral accuracy with the order of basis functions 相似文献
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《Microwave Theory and Techniques》2009,57(8):2015-2020
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Optimization of the Perfectly Matched Layer for the Finite-Element Time-Domain Method 总被引:1,自引:0,他引:1
Movahhedi M. Abdipour A. Ceric H. Sheikholeslami A. Selberherr S. 《Microwave and Wireless Components Letters, IEEE》2007,17(1):10-12
We present a new formulation to implement the complex frequency shifted-perfectly matched layer (CFS-PML) for boundary truncation in 2-D vector finite-element time-domain method directly applied to Maxwell's equations. It is shown that the proposed method is highly absorptive to evanescent modes when computing the wave interaction of elongated structures or sharp corners. The impact of the CFS-PML parameters on the reflection error is investigated and optimal choices of these parameters are derived 相似文献
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We describe a mixed finite-element time-domain algorithm to solve transient Maxwell equations in inhomogeneous and doubly dispersive linear media where both the permittivity and permeability are functions of frequency. The mixed finite-element time-domain algorithm is based on the simultaneous use of both electric and magnetic field as state variables with a mix of edge (Whitney 1-form) and face (Whitney 2-form) elements for discretization of the coupled first-order Maxwell curl equations. The constitutive relations are decoupled from the curl equations and cast in terms of (auxiliary) ordinary differential equations involving time derivatives. Permittivity and permeability dispersion models considered here are quite general and recover Lorentz, Debye, and Drude models as special cases. The present finite-element time-domain algorithm also incorporates the perfectly matched layer absorbing boundary conditions in a natural way. 相似文献
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Genetic Algorithm in Reduction of Numerical Dispersion of 3-D Alternating-Direction-Implicit Finite-Difference Time-Domain Method 总被引:2,自引:0,他引:2
A new method to reduce the numerical dispersion of the 3-D alternating-direction-implicit finite-difference time-domain method is proposed. Firstly, the numerical formulations are modified with the artificial anisotropy, and the new numerical dispersion relation is derived analytically. Moreover, theoretical proof of the unconditional stability is shown. Secondly, the relative permittivity tensor of the artificial anisotropy can be obtained by the adaptive genetic algorithm. In order to demonstrate the accuracy and efficiency of this new method, several examples are simulated. The numerical results and the computational requirements of the proposed method are then compared with those of the conventional method and measured data. In addition, the reduction of the numerical dispersion is investigated as the objective function of the genetic algorithm. It is found that this new method is accurate and efficient by choosing a proper objective function 相似文献
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Wireless Personal Communications - In this paper, a new time-domain (TD) solution is proposed for analyzing the diffraction of ultra wideband (UWB) signals in three dimensional (3-D) scenarios. In... 相似文献
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Simulation of Electromagnetic Transients of the Bus Bar in Substation by the Time-Domain Finite-Element Method 总被引:1,自引:0,他引:1
《Electromagnetic Compatibility, IEEE Transactions on》2009,51(4):1017-1025
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《Antennas and Propagation, IEEE Transactions on》2008,56(11):3501-3509
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《Electron Devices, IEEE Transactions on》2009,56(8):1729-1735
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求解椭圆方程的局部间断Galerkin(LDG)方法具有精度高、并行效率高的优点,且能适用于各种网格。文章提出采用LDG方法来求解IC版图中电势分布函数满足的Laplace方程,从而给出了一个提取互连线电容的新方法。该问题的求解区域需要在矩形区域内部去掉数量不等的导体区域,在这种特殊的计算区域上,通过数值测试验证了LDG方法能达到理论的收敛阶。随着芯片制造工艺的发展,导体尺寸和间距也越来越小,给数值模拟带来新的问题。文章采用倍增网格剖分方法,大幅减小了计算单元数。对包含不同数量和形状导体的七个电路版图,用新方法提取互连线电容,得到的结果与商业工具给出的结果非常接近,表明了新方法的有效性。 相似文献
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Sauveplane J.B. Tounsi P. Deram A. Scheid E. Chauffleur X. 《Advanced Packaging, IEEE Transactions on》2007,30(4):789-794
A 3-D electrical finite-element model (FEM) for the design of an ultra-low on-state resistance power MOSFET device is presented. Model building and layer conductivity are discussed to take into account microscopic, technological, and electrical effects, such as metal step coverage and MOS behavior of each elementary cell of the transistor. Model simplifications are also presented to ensure time-efficient simulations. FEM gauging is then achieved, by comparing simulation results to electrical measurements, on devices subjected to top metallization debiasing effects. Simulations show a good agreement with measurements for result errors at less than 2%. The aim of this paper is to provide an accurate estimation of the contribution of parasitic elements such as the shape and number of power bonding wires or top metallization thickness to power device on-state resistance (RON). The 3-D electrical FEM is a mandatory first step towards an accurate electrothermal FEM for the design of efficient power products. 相似文献
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提出一种基于半导体器件漂移扩散模型并结合交替方向隐式时域有限差分(ADI-FDTD)法的新型全域FDTD法.该方法时间步长的选择取决于数值精度而非稳定性,克服了传统全域FDTD法为了保持数值稳定性,时间步长的选取受限于Courant稳定性条件的问题.该方法的复杂度稍微增加,但是通过增加时间步长,减少计算时间、提高计算速度.该方法的主要特点是模拟一个简单的二极管分布开关电路. 相似文献
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Banerjee S.R. Chenglin Zheng Drayton R.F. 《Advanced Packaging, IEEE Transactions on》2007,30(2):200-208
Microstrip interconnects with a V conductor are designed, fabricated, and measured to provide a compact solution for designs requiring low characteristic impedance lines. S-parameter curves are shown up to 35 GHz for 0.5-cm-long lines. The 308-mum-deep V structure produces a 33.8-Omega line with strong standing waves and reflections under 5 dB. To further reduce the impedance, a partial shield is added that results in 6.7 times reduction of signal line width, near elimination of open-end effect, and excellent correlation with a standard 15-Omega microstrip up to 25 GHz. A filter demonstration shows near ideal behavior in the 3 dB response and low return loss when compared to a similar conventional design. 相似文献
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Stefano Grivet-Talocia 《AEUE-International Journal of Electronics and Communications》2004,58(4):293-295
The Time-Domain Vector Fitting (TD-VF) algorithm for macromodeling of linear multiport systems is presented. A rational approximation for the system matrix transfer function is easily derived from transient input/output port responses. Several validations illustrate the high accuracy of the method. 相似文献
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《Microwave Theory and Techniques》1987,35(4):383-395
The need for high-resolution distributive dosimetry demands a numerical method capable of handling finely discretized, arbtrarily inhomogeneous models of biological bodies. At present, two of the most promising methods in terms of numerical efficiency are the fast-Fourier-transform conjugate gradient method (FFT-CGM) and the finite-difference time-domain (FD-TD) method. In this paper, these two methods are compared with respect to their ability to solve the 2-D Iossy dielectric cylinder problem for both the TM and TE incident polarizations. Substantial errors are found in the FFT-CGM solutions for the TE case. The source of these errors is explained and a modified method is developed which, although inefficient, alleviates the problem and illuminates the difficulties encountered in applying the pulse-basis method of moments to biological problems. In contrast, the FD-TD method is found to yield excellent solutions for both polarizations. This, coupled with the numerical efficiency of the FD-TD method, suggests that it is superior to the FFT-CGM for biological problems. 相似文献